Upto what frequency IR could be used to transmit data

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Ahmmed Razu

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I am going to transmit some data through USART over IR at 500kbps (baud rate). I have transmitted data but receiving some garbage value. Now i want to know upto what frequency IR could be used?
 

You have to refer to the datasheet or any technical document if the maximum baud rate is mentioned. I don't think general IR diodes & receivers can work on such high speed data transmission. Some IrDA IC's allows max data rate of upto 115 kbps. Try within 100kbps.
 

IR links in fiber optics are past 1GBPS/lane using laser
diodes and photodiodes, along with well crafted drivers
and sense amps. But all of these pieces are selected
with some effort.

Not every IR emitter may be fast enough especially
if you are going to zero current. Usually a bilevel current
is used on laser diodes such that transitions in both
directions are fast (diode impedance being low in both
cases, enough to support data rate w/ parasitics).

Time for you to start debugging. Get out the 'scope and
see what relation detector signal has to driver signal,
as a start.
 

Depends on your medium. In fiber, your path loss is low and constant so like dick_freebird said you can use bilevel current, which allows much faster response time of the circuitry. If you're transmitting over air you probably have to use either some additional modulation or operate your LED fully on/off, both of which impose great speed limitations.
 

could you or dick_freebird upload any IR Driving circuit for high speed switching? bi level or other type?
i am using ST-1KLA as a receiver.
 

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